St. Tammany farmer. [volume] (Covington, La.) 1874-current, 1887-07-02
EARTH UPHEAvALS.


There is something about those
mighty displays Of natures forces
which we term earthquakes that inter-
ests and fascinates vast majority OF
mankind. Probably few readers are
aware that since 1888 no less than $50
earthquakes have occurred in various
parts Of New England and the Atlantic
States. Previous to the recent destruct-
i've earthquake at Charleston the most
severe shock known in this country was
at New Madrid. Mo-, in 1871. Tho
ground rose in huge waves, which burst.
and volumes Of water. sand. and pit
coal were thrown high ~ the tops OF
the trees. The forests waved like stand
ing corn in gale Of wind, and an area
seventy miles long by thirty miles wide
was submerged and became . swamPy
lake.
On August Is. 1868. fearful earth.
quake took place in Peru. which laid
waste much Of the country lying be-
tween the Andes and the Pacific. The
shocks were felt through distance OF
400 miles, north and south. and three
important cities were destroyed. At
Arequipa, in Peru. forty miles from the
sea, q slight undulatory shock was felt.
followed by others 50 violent that in five
minutes not house was standing in
that city Of 44.OOO inhabitants. A sub
terranean rumbling, like the rush Of an
avalanche. was heard above the crash,
and cloud of dust rose in the still Air
over the city. On the seacoast were
situated Iquique and Arica-both were
destroyed by the shocks, and over
whelmed by tremendous wave. The
ocean thus took up the vibrations OF
the land, and waves Of tremendous
volume were put in motion. which
rolled. not only upon the coast. but
away from it with . velocity in the deep
ocean Of not less than 400 miles an
hour. The great wave-for one was OF
much greater volume than the others
has been estimated at upward of 200
miles breadth. with . length along its
curved crest Of 5000 miles. This rolled
into the harbor Of Yokohama, in Japan.
10, 500 miles distant, and was felt ut Port
Fairy. in South Victoria, distant nearly
one-half Of the earth's circumference.
The opening and closing Of assures
and chasms in the ground during earth
auakes is common phenomenon. Men.
animals and dwellings are sometimes
swallowed in them and forever disap-
pear. In l848 an earthquake shook a
large portion of New Zealand. and a
assure Of great depth opened along
chain Of mountains from one thousand
to four thousand feet high. extending
sixty miles. but Of not more than eigh-
teen inches in average width. During
the Calabrian earthquake Of 1888 the
surface of the ground opened and
closed in immense assures, by means
OF which new lakes were formed and
others drained or were dried up. At
Jerocarne the earth is described, BY Sir
Charles Lyell. rs lacerated in an extra
ordinary manner. "Fissures ran in
every direction. like cracks in broken
pane Of glass" In another instance.
several dwellings were engulfed in a
fissure, and were found to be jammed.
with their contents. into = compact
mass. Chasms Of immense length and
depth were formed. Some were cres-
cent-shaped. and . mile in length. The
plains Of Calabria were covered in
many places with circular hollows from
one foot to three or four feet in diameter.
Some of these were filled with water.
others with dry sand.
But changes in the earth's crust Oc-
cur during earthquakes. on a still
grander scale. Evidences of local dis
turbance, however disastrous it may
have been. are often effaced il not for
gotten in a few centuries, frequently
in q few years. But the slow upheaval
of mountain chains and the dislocatiOn
of strata through profound depths are
results which have been the subject Of in
quiry by the worlds leading geologists.
Whether the central portions Of the
earth be fluid or not. it is quite certain
that heat increases as we descend; and
it is estimated by Sir Charles Lyell that
the heat at depth Of twenty-five miles
would be sufficient to melt granite. and
at thirty-four miles to render fluid or
incandescent every known substance.
We have no means Of knowing the con-
dition Of matter under the enormous
pressure which prevails Mt depth Of
thirty four miles. and are most con:
cerned with the fact that the heat Of
fusion exists at no very great depth be-
meath the surface. The earth's crust
is, therefore, its cooled exterior.
1t is found that nearly all rocks con-
.ract by cooling and expand by heat.
Lyell estimates that sandstone mile in
thickness. and heated to 900 degrees
Fahrenheit, would expand so IS to lift
a mass Of rock upon it ten feet above its
former level; and il a mass Of the
earth's crust equally expansible. fifty
miles in thickness, be heated to 800 de-
grees. it would rise 1,50O feet. From
cooling we have the reverse effect
shrinkage. contraction. lateral pres
sure. and ultimately blending Of the
strata. The strain thus produced will
at length cause fracture. and the vi
bratiOn that results is an earthquake.
This form Of tension is being cOntinu.
ally and everywhere produced in the
earth's crust, and there is probably nc
instant of time when that crust is en-
tirely free from vibrations. There is
nothing" observes Darwin. mot even
the wind that blows, 50 unstable as the
level of the crust Of the globe. Cas-.